The government has moved to maintain air-sea rescue helicopters at four coastal stations after a security muddle over a £6bn aircraft order. Concern for safety offshore has prompted the transport department to tender for interim, five-year services while the longer-term contract is reworked.

The move coincides with an expected backtrack over the government's original plans to streamline the coastguard service, which caused an outcry when they were announced last year. The rescue helicopters work for the Maritime and Coastguard Agency, which prepared the cuts.

The transport secretary, Philip Hammond, said the interim helicopter service would be similar to the one offered by RAF Sea King helicopters controlled by coastguard bases at Portland in Dorset, Lee-on-Solent in Hampshire, and at Shetland and the Isle of Lewis in Scotland. The longer-term contract was stopped after it emerged in February the preferred bidder, Soteria, had been given access to confidential security information.

Soteria had planned to operate US Sikorsky helicopters for the agency out of 12 bases, some of them run by the Royal Navy and the RAF. Hammond said the Sea Kings, which the Ministry of Defence plans to withdraw from service in 2016, would continue work while discussions continue on "the long-term provision of search-and-rescue helicopter capability".

The coastguard announcement is expected to ease planned closures of its 18 centres, keeping 11 going round-the-clock, rather than the agency's original plan to retain eight, with only three operating 24 hours.

The change is also expected to reduce job losses, originally estimated at 250, which the House of Commons transport committee said in a recent report "raises serious concerns that safety will be jeopardised if these proposals proceed".

The Labour chair of the committee, Louise Ellman, said the coastguard proposals were "seriously flawed" and had little support from staff and the public.